Inconsistency between Control#getBounds and Control#getSize

[akoch-yatta]

Description
Control#getBoundsInPixels and Control#getSize have an inconsistent way to calculate its value. Control#getBoundsInPixels takes x/y into consideration to scale down from px to pt, Control#getSize. This can lead to different values for width and/or height for the same px value.

Reproduction

Execute the Snippet below with a primary monitor on 125% and you see the following output:

Bounds height 201
Size height 202

So, getBounds says the height is 201pt, but getSize claims it to be 202pt

package org.eclipse.swt.snippets;

import org.eclipse.swt.*;
import org.eclipse.swt.graphics.*;
import org.eclipse.swt.widgets.*;

public class Snippet385 {

	public static void main (String [] args) {
		final Display display = new Display ();
		final Shell shell = new Shell (display);
		shell.setText("Snippet385");
		Composite composite = new Composite(shell, SWT.None);
		List list = new List(composite, SWT.NONE);
		list.add("List item 1 with a very very long name and no end");

		composite.setBounds(0, 0, 250, 250);
		list.setBounds(0, 49, 250, 201);
		Rectangle bounds = list.getBounds();
		Point size = list.getSize();
		if (bounds.height != size.y) {
			System.out.println("Bounds height " + bounds.height);
			System.out.println("Size height " + size.y);
		}

		shell.setSize(400, 750);
		shell.open ();
		while (!shell.isDisposed ()) {
			if (!display.readAndDispatch ()) display.sleep ();
		}
		display.dispose ();
	}
}

Expected Behavior
Control#getBoundsInPixels and Control#getSize should always return the same values regarding width and height

Necessary configuration:
Primary monitor on 125% for the Snippet
Also need to set -Dswt.autoScale=quarter

Additional knowledge
Fix for this could be to use getBoundsInPixels instead of getSizeInPixels and scale width and height of it down.

[amartya4256]

The underlying reason for this issue was, getSize and getBounds used two different methods, DPIUtil:scaleDown and scaleBounds respectively. They both have different implementations - leading to different results. eclipse-platform/eclipse.platform.swt#2200 should unify their behaviour to a more precise value.